Measurement Computing eZ-Record rev.2.1 - Manual (Page 30)

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eZ-Record Manual January 2001
A
UTORANGE
Autoranging is a procedure that automatically sets the input full scale voltage
(FSV) range for input channels. FSV is set by measuring a representative sample
of real-time data. It is performed only on active channels.
Autoranging works best if you supply the same type live data you will be
capturing during data acquisition. If you are performing an averaged count, the
count will automatically reset to one. If your capture mode is triggered, you will
have to supply a trigger. If your capture mode is Free Run, the autoranging
process starts automatically.
When the Auto Range window opens, the number at the bottom of each column
is the Current FSV are the same values that were entered in the Vpeak column in
the Channel Setup window. These values are immediately replaced when the
Auto ranging process begins.
For example, if in the Autorange Setup window you specify Maximum FSV as 80,
Minimum FSV as 45, Increasing factor as 1.333 and Decreasing factor as 1.333 the
following will occur.
For the first iteration, if the peak value of the data block is greater than 0.8 times
the FSV set in the Channel Setup window, or less than 0.45 times the FSV, then the
Current FSV fields are changed to 1.333 times the peak found in the acquisition.
For the rest of the iterations, if the instantaneous peak value is greater than 80
percent of the Current FSV, the Current FSV is recalculated to 1.333 times the peak
found in the acquisition. This process will continue for 100 iterations, or you may
click the OK button when you are satisfied with the input range.
If the Capture Mode is Input Channel (Trigger Mode), the Auto Range process
waits for a trigger.
Monitoring the Instantaneous Signal Level
The instantaneous peak value is graphically displayed in the vertical bars.
Yellow= signal range is from 0 to the minimum Full Scale voltage set in the
Autorange Setup window.
Green = signal range is from the minimum to the maximum of the Full Scale
voltage set in the Autorange Setup window.
Red = signal range is over the maximum of the Full Scale voltage set in the
Autorange Setup window.